The objectives of the project are to develop methods for the precise study of genetic and genetic biochemical processes in mammalian somatic cells; to apply these to gene identification and localization; and to study gene regulation in health and disease. The current efforts in this program are aimed at producing additional mutations, characterizing and identifying their specific effects, producting of specific hybrids that will permit gene localization on the human chromosomes, and identification of gene regulatory mechanisms in normal differentiation processes and in developmental diseases.